| 摘要 |
<p>Electric permanent-magnet synchronous motor comprising a stator provided with ferromagnetic polarities, a rotor featuring an inner through-cavity and adapted to translate along its own axis (X) relative to the stator, said rotor being in turn provided with a plurality of permanent magnets, a rotating driving shaft (4) fitted into the rotor and axially stable relative to the stator, actuator means that are adapted to cause the rotor to displace axially relative to the stator and, as a result, the driving shaft as a function of the rotation speed thereof, and that comprise one or two bridging members, each one of which is comprised of two rigid plates hinged on to each other, wherein one such plate is also engaged with the rotor, while the other one is also engaged with the driving shaft. The driving shaft is smooth and even externally so that it is by no means able to engage the rotor; as a result, the driving torque supplied by the rotor is transmitted to the rotating driving shaft by passing through said rigid plates of said bridging members. As the rotation speed of the rotor increases, owing to the effect of the resulting centrifugal force said rigid plates are caused to move closer to each other by rotating about the commonly shared hinge, and such movement causes the rotor to be pulled partially out of the stator. When on the contrary the motor stops, the force of attraction between the stator and the permanent magnets of the rotor causes the latter to move back into its normal position, in which it is fully inserted in the stator.</p> |
